username validation text code example
Example 1: username validation
<html>
<head>
<title></title>
</head>
<body>
<form method="post" action="">
username:<input type="text" id="name" onkeyup="validation()">
</form>
</body>
<script type="text/javascript">
function validation(){
var username=document.getElementById("name").value;
var usernamepattern=/^[A-Za-z .]{3,15}$/;
if(usernamepattern.test(username))
{
document.getElementById("name").style.backgroundColor='yellow';
}
else
{
document.getElementById("name").style.backgroundColor='red'; }
}
</script>
</html>
Example 2: username validation
const checkUsername = () => {
let valid = false;
const min = 3,
max = 25;
const username = usernameEl.value.trim();
if (!isRequired(username)) {
showError(usernameEl, 'Username cannot be blank.');
} else if (!isBetween(username.length, min, max)) {
showError(usernameEl, `Username must be between ${min} and ${max} characters.`)
} else {
showSuccess(usernameEl);
valid = true;
}
return valid;
}Code language: JavaScript (javascript)